Bangkok, Thailand (CNN) -- A grenade attack on a group of police officers in Thailand's troubled south killed one and wounded 44 on Wednesday, authorities said.

The group was getting ready to begin their morning duties outside a police station in Pattani province when a grenade was tossed at them, said an officer at the station.

Around the same time, a car bomb exploded near the same police station, wounding four more people but causing no fatalities.

Deadly violence in the south of Thailand has for years been blamed on a group of separatists who vowed to turn the region into a Muslim state, launching attacks on police and government-operated schools.

Three provinces in the region -- Pattani, Yala and Narthiwat -- were annexed into Thailand in the early 1900s.

The people in the region are Malay-speaking Muslims who feel few emotional ties to the predominantly Buddhist country. They have long complained about discrimination in education and employment.